A significant amount of research has focused on the synthesis, characterization, and properties of 2D and quasi-1D layered materials since graphene’s remarkable discovery in 2004. Specifically, researchers have gravitated towards low-dimensional materials as the most promising way to construct cheaper and faster devices that can improve state-of-the-art silicon-based technology within the electronics industry. Examples include the transition metal chalcogenides, a class of van der Waals materials that exhibit unique optical and electronic properties making them excellent candidates for some next-generation electronics applications.1-2 Both ZrTe3 and HfTe3 are notable transition metal chalcogenides due to their unique properties, such as the rare coexistence of both charge density wave transitions and superconductivity without physical or chemical modification.3-6 Furthermore, ZrTe3 exhibits an exceptionally high current density (~100 MA/cm2) in comparison to copper interconnects (~2-3 MA/cm2), the present industry standard used in conjunction with silicon-based technology.7-8 Alternatively, studies with HfTe3, the isostructural counterpart of ZrTe3, have been very limited due to the difficulty in synthesizing this material and inconsistencies in the literature.3,6,9
This talk will address these gaps in the literature and focus on novel synthetic pathways in isolating HfTe3. Polycrystalline HfTe3 was obtained using the solid state approach at 550 °C followed by either immediate quenching, slow-cooling, or natural cooling. We also determined that we could access single crystalline HfTe3 at 530 °C using polycrystalline HfTe3 as a precursor under chemical vapor transport (CVT) conditions. We further extended our work with HfTe3 to single crystalline HfxZr1-xTe3 alloys with the ultimate goal of establishing novel synthetic routes, and exploring the possibility of tuning properties by alloying. Using the favored temperatures of single crystalline HfTe3 (530 °C) and ZrTe3 (850 °C), we were able to acquire specific phases of HfxZr1-xTe3 (x = 20, 40, 80) via the CVT approach. Finally, we extended our work to other transition metal chalcogenide alloys including TixZr1-xTe2 and TixHf1-xTe2. Using the favored temperatures of TiTe2(800 °C), ZrTe2 (900 °C), and HfTe2 (900 °C), we were able to isolate single crystalline TixZr1-xTe2 compositions (x = 30, 50, 80) and TixHf1-xTe2 compositions (x = 20, 40, 80) under CVT conditions.
- Island, J.; Molina-Mendoza, A.; Barawi, M.; Biele, R.; Flores, E.; Clamagirand, J.; Ares, J.; Sánchez, C.; van der Zant, H.; D’Agosta, R.; Ferrer, I.; Castellanos-Gomez, A. 2D Mater. 2017, 4, 022003.
- Chhowalla, M.; Shin, H.; Eda, G.; Li, L.; Loh, K.; Zhang, H. Nat. Chem. 2013, 5, 263-275.
- Li, J.; Peng, J.; Zhang, S.; Chen, G. Phys. Rev. B 2017, 96, 174510.
- Starowicz, P.; Battaglia, C.; Clerc, F.; Despont, L.; Prodan, A.; van Midden, H.; Szerer, U.; Szytuła, A.; Garnier, M.; Aebi, P. J. Alloys Compd. 2007, 442, 268-271.
- Takahashi, S.; Sambongi, T.; Brill, J.; Roark, W. Solid State Comm. 1984, 49, 1031-1034.
- Denholme, S.; Yukawa, A.; Tsumura, K.; Nagao, M.; Tamura, R.; Watauchi, S.; Tanaka, I.; Takayanagi, H.; Miyakawa, N. Sci. Rep. 2017, 7, 45217.
- Geremew, A.; Bloodgood, M.; Aytan, E.; Woo, B.; Corber, S.; Liu, G.; Bozhilov, K.; Salguero, T.; Rumyantsev, S.; Rao, M.; Balandin, A.A. IEEE Electron Device Lett. 2018, 39, 735-738.
- Geremew, A.; Rumyantsev, S.; Bloodgood, M.; Salguero, T.; Balandin, A. Nanoscale 2018, 10, 19749-19756.
- Brattås, L.; Kjekshus, A. Acta Chem. Scand. 1972, 26, 3441-3449.